gstreamer怎么用c语言抽帧

你可以使用GStreamer库来在C语言中抽取帧。下面是一个简单的示例代码，展示了如何使用GStreamer来抽取视频帧：
#include <gst/gst.h>

static gboolean bus_call(GstBus *bus, GstMessage *msg, gpointer data) {
GMainLoop *loop = (GMainLoop *)data;

switch (GST_MESSAGE_TYPE(msg)) {
case GST_MESSAGE_EOS:
g_print("End of stream\n");
g_main_loop_quit(loop);
break;
case GST_MESSAGE_ERROR: {
gchar *debug;
GError *error;

gst_message_parse_error(msg, &amp;error, &amp;debug);
g_free(debug);

g_printerr("Error: %s\n", error->message);
g_error_free(error);

g_main_loop_quit(loop);
break;
}
default:
break;
}

return TRUE;
}

int main(int argc, char *argv[]) {
GMainLoop *loop;
GstElement *pipeline, *source, *decoder, *sink;
GstBus *bus;

gst_init(&amp;argc, &amp;argv);
loop = g_main_loop_new(NULL, FALSE);

if (argc != 2) {
g_printerr("Usage: %s <video file>\n", argv[0]);
return -1;
}

pipeline = gst_pipeline_new("video-player");
source = gst_element_factory_make("filesrc", "file-source");
decoder = gst_element_factory_make("decodebin", "decoder");
sink = gst_element_factory_make("autovideoconvert", "video-sink");

if (!pipeline || !source || !decoder || !sink) {
g_printerr("Not all elements could be created.\n");
return -1;
}

g_object_set(G_OBJECT(source), "location", argv[1], NULL);

gst_bin_add_many(GST_BIN(pipeline), source, decoder, sink, NULL);
gst_element_link(source, decoder);
gst_element_link(decoder, sink);

g_signal_connect(decoder, "pad-added", G_CALLBACK(on_pad_added), sink);

bus = gst_pipeline_get_bus(GST_PIPELINE(pipeline));
gst_bus_add_watch(bus, bus_call, loop);
gst_object_unref(bus);

gst_element_set_state(pipeline, GST_STATE_PLAYING);
g_main_loop_run(loop);

gst_element_set_state(pipeline, GST_STATE_NULL);
gst_object_unref(GST_OBJECT(pipeline));
g_main_loop_unref(loop);

return 0;
}
登录后复制
这个示例代码创建了一个GStreamer管道，并使用filesrc元素从指定的视频文件中读取数据。然后，使用decodebin元素解码视频流，并使用autovideoconvert元素进行格式转换。你可以根据需要修改和扩展这个代码，以满足你的具体需求。
请确保在编译时链接GStreamer库，并在运行代码之前设置正确的视频文件路径。